Design And Research On The Low-gravity Simulation Test-bench Of Driling & Sampling Avoidance Mechanism On Lunar Surface

Currently, China’s Moon probe program is preparing the third stage to fulfill backing-out unmanned lunar sampling. The lunar drilling sampler that our country developed, after its drilling sampling, could provide escape space for the risers by avoidance mechanism unlocking and expansion with shaping mechanism. Successfully unlocking and expansion of the avoidance mechanism is the key to fulfill the task. So we should develop special equipment to simulate lunar environment on earth which undergoing reliability test for avoidance mechanism. In order to verify its reliability, the significance of this subject is to develop a low-gravity simulation test-bench to simulate lunar environment and test its comprehensive performance.Ground low gravity environment simulation includes free fall, parabolic flight, offset equilibrant and so on. Combining actual situation of the project and comprehensive consideration of various factors, the slope force equivalent method which has high reliability and more suitable for avoidance mechanism is chosen finally. According to the technical index of the project, the key mechanical parts of the low-gravity simulation test-bench are designed in detail, including avoidance mechanism supporting device, normal supporting device, press-release device, lifting device and so on. The motion control system and data acquisition system of the test-bench are also designed.According to the principle of low-gravity simulation test-bench, the mechanical properties of the low-gravity simulation test-bench were analyzed, including analysis of rolling friction torque with normal supporting, the impact of cable and sensor, the adjustment of landing attitude, dynamic analysis for locking impact on avoidance mechanism. Based on ADAMS to do the kinematic analysis and acquire the whole kinetic characteristic process on the lunar surface and the whole kinetic characteristic process was carried out on test-bench.Carried out the whole process kinematics test analysis of the avoidance mechanism in virtue of this test-bench. With the comparison between test and simulation, the feasibility and correctness of the test-bench were verified. In order to provide data for dynamic analysis, measuring the acceleration of different positions on avoidance mechanism. Carried out test of locking impact characteristics on avoidance mechanism and verified its feasibility.Error analysis of the test-bench was carried out, including the error caused by mechanical structure and the precision of external device. With the error analysis, acquired the factors that affect the accuracy of the test-bench and evaluated the errors caused by these factors.Through information access, theory analysis, structure design, simulation and experiment, the development work of low-gravity simulation test-bench is completed. Providing technical support for the implementation of China’s lunar exploration project safety.